Introduction: There is an urgent need to define the neurobiological and cognitive underpinnings of suicidal ideation and behavior in veterans with traumatic brain injury (TBI). Separate studies implicate frontal white matter systems in the pathophysiology of TBI, suicidality, and impulsivity. We examined the relationship between the integrity of major frontal white matter (WM) systems on measures of impulsivity and suicidality in veterans with TBI.
Methods: Fifteen male veterans with TBI and 17 matched healthy controls (HC) received clinical ratings, measures of impulsivity and MRI scans on a 3T magnet. Diffusion tensor imaging (DTI) data for the genu and cingulum were analyzed using Freesurfer and FSL. Correlations were performed for fractional anisotropy (FA) (DTI) values and measures of suicidality and impulsivity for veterans with TBI.
Results: Significantly decreased in FA values in the left cingulum (P = 0.02), and left (P = 0.02) and total genu (P = 0.01) were observed in the TBI group relative to controls. Measures of impulsivity were significantly greater for the TBI group and total and right cingulum FA positively correlated with current suicidal ideation and measures of impulsivity (P <0.03).
Conclusion: These data demonstrate a significant reduction in FA in frontal WM tracts in veterans with mild TBI that was associated with both impulsivity and suicidality. These findings may reflect a neurobiological vulnerability to suicidal risk related to white matter microstructure.
The Brain Institute, University of Utah, Salt Lake City, Utah (Drs Yurgelun-Todd, McGlade, Churchwell, and Lopez-Larson, and Mr Bueler); University of Utah School of Medicine, Salt Lake City, Utah (Drs Yurgelun-Todd and Lopez-Larson); VA VISN 19 Mental Illness Research, Education and Clinical Center (MIRREC), Salt Lake City, Utah (Drs Yurgelun-Todd, McGlade, and Lopez-Larson); VA VISN 19 MIRECC, Denver, Colorado (Dr Brenner); Department of Psychiatry, University of Colorado Denver, School of Medicine, Denver, Colorado (Dr Brenner); Department of Physical Medicine and Rehabilitation, University of Colorado Denver, School of Medicine, Denver, Colorado (Dr Brenner); and Department of Neurology, University of Colorado Denver, School of Medicine, Denver, Colorado (Dr Brenner).
Corresponding Author: Deborah A. Yurgelun-Todd, PhD, The Brain Institute, 383 Colorow Dr, Salt Lake City, UT 84108 (firstname.lastname@example.org).
This work was supported by research grants from Merit review 5I01CX000253-02 and VISN 19 MIRECC.